Improvement in fire-alarm thermometers



A. GUEST.

Thermostat.

Patented Oct. 18, 1870.

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dtniwl fibers {some (refine AUGUSTA GUEST, OF BROOKLYN, NEW YORK.

Letters Patent No. 108,352, dated October 18, 1870.

IMPROVEMENT IN FIRE-ALARM THERMOMETERS.

The Schedule referred to in these Letters Patent and making part. of thesame.

To all whom it may concern:

Be it known that I, Mrs. Aueus'ra G onsr, of Brooklyn, in the county ofKings and State ofNew York, have invented a new and improved lirc-alarnr Thermometer; and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art to make and use the same, reference being had to theaccompanying drawing, forming part of this'spccification.

Figures 1 and 2 are transverse sections of my improved tire-alarmthermometer, showing modifications in the'construction of the same.

Similar letters of reference indicate corrcsp'olnling parts.

Tire object of this invention .is to construct an instrument for closingthe circuit of an electric firealarm, as soon as the atmosphere whichsurrounds said instrument has reached a certain degree of heat.

The invention relates to the use of a glass thcrmonieter containing(pricksilvcr.

The thermometer is 'to be broken when the stated dcgrcc oi heat has beenreached, and will then deposit its metallic contents into an outervessel, which re ccives the two wires from the alarm instrument andbattery.

The quicksilver, uniting the ends of said wires, cslablishcs a metalliccircuit, and cti'ccts the operation of the alarm.

The alarm-thermometers herctoiorc in use had the ends of the wiresinserted in the respective ends of the glass or other vessel containingthe mercury, but were incilicienton account ol the unequal expansion andcontraction of the wire and glass under the ordinary variations oftemperature, whereby air was let into the instrument or the glassbroken.

These devices were also unrcliablc,as'thc least dcl'cct of the platinapoints inserted in the mercury were apt to corrode the latter, andbecause, furthermore,

rats and "mice, by pulling or moving the wires, were apt to render thewhole apparatus useless.

My invention consists chiefly in the application of asealed-bulb orvessel, A, containing mercury, to an outer vessel, B, and the wires 0 D,that lead to a suitable alarm instrument and battery.

The bulb or vessel A, when burst by-thc action of the expanding mercury,with or without the aid of an outer spring, E, will discharge itscontents into the vessel B, so that the ends of the wires 0 D will beunited by the mercury. The electric current is thereby established, andthe alarm operated.

The invention consists also in the combination with said apparatus of aspring or springs, E, of suitablekind. The same serve to break the bulband open the same for discharging the mercury immediately after the bulbhas been burst by the latter.

For this purpose the-spring may either be applied to pull at one end ofthe bulb, as in jig. 1, or to push againstthe same, as in 2, and itmaybe concealed within the vessel B, or arranged (i'utside of the same,one end of the bulb being sccuret by a wire or other fastening, u, whenthe spring is applied to pull.

The invention consists also in the arrangement of the said vessel B,which contains the bulb A and the ends of the wires 0 D to connect thelatter by the mercury from the former whenever the bulb is burst.

The vessel 15 may either be made in form shown in lig. l, i. a, opcii ontop and sides to receive air, or it may be a case, as in fig. .5,perforated to admit air, or of other suitable form.

It will be seen that the condition or disturbance of the wires duringinactivity will not not affect the utility or or effectiveness of myapparatus.

Having thus described my invention,

.l claim as new and desire to secure by Letters latcnt- I a l. Thescaled bulb or thermometer, combined with two wires, so that by thebursting at said bulb a metallic connect-ion between the wires and aconsequent electric circuit will be established, substantially as hereinshown and described.

2. Tlie spring or springs 1), combined with the bulb or thermometer, toaid in parting the same when broken, substantially as herein shown anddescribed.

The vessel B,containing the bulb or thermometer A, and the ends of thewires 0 D, for operating, substantially as herein shown and described.

' AUGUSTA GUEST.

Witnesses A. V. Bmnsnn, GEO. W. Mamas.

